Document viewers allow online viewing of documents in browser windows. High fidelity document rendering displays the document in the same view as if it were printed, and so is sometimes referred to print view. When comments are attributed to such a view, the comments may not have any relation to the corresponding document text, as the on screen anchors and comments typically are painted over the document. When the source document changes, the comment anchors may become invalid. For example, if an editing user makes changes to the text in a MS-Word document and attaches a comment, when the original user accepts the comments the text to which the document is attached goes away but the comment remains.
An alternative approach inserts the comments locations in-line with the text itself in the source document. As text moves from revision to revision, the comment moves along with it. However, embedding the information within the document can present problems around offline document editing, such as editing and commenting on the desktop, security document conversion and concurrent editing and review.
Another approach has attempted to solve this problem using an HTML view of the document. This allows for in-lining the comment locations in the text and provides some facility for tracking comments between revisions. However, an HTML rendering is not a high fidelity rendering and the comments are lost when the document is taken offline.